Sweet Itch


Sweet itch, also known as culicoides hypersensitivity, is a skin disease caused by an allergy to midge bites. It presents as pruritis or itching, usually of the mane and tail but can also occur on the underside of the abdomen.

Preventing or minimising bites is the most effective way to control symptoms. This needs forward planning and to be started early, i.e. before the midges start biting.

Recommendations for the management of sweet itch:

Consult your vet early on in the year before the midges start biting in earnest. Your vet will also make sure it is sweet itch and not another cause of itchiness, such as pinworm, lice or another allergy.

Good insect control is essential to prevent the midges biting. This can be accomplished in a number of ways:

  • Daily application of insect repellents, use of fly sheets or rugs and stabling during times of high midge activity (dawn and dusk). Some people have success with longer lasting pour on fly repellents, please speak to your vet for recommendations.
  • During the summer when midge activity is high, stabling from 16:00pm until 18:00am is recommended.
  • It is a good idea to move affected horses to open, more exposed fields with good breeze (midges are weak fliers and get blown away with a wind more than 4mph! ) and keep affected horses and ponies well away from woodland and water - especially standing water such as ponds.
  • Getting a fan for the stable will also deter midges.
  • Many horses or ponies with this condition may need treatment to control the itch and sometimes resolve secondary skin infections. Often topical treatment is very effective (and has fewer potential side effects) but sometimes tablets and / or injections are needed.
  • Some people have used nicotinamide based oral supplements and topical ointment. This balances the natural immune reaction in the horse to the midge bites. This treatment should be started before the first sweet itch signs are seen, so around about March.

There are many other supplements that are reported to alleviate signs, but none have been proven effective in all cases. Medication is available that can help decrease the severity but as yet, there is no cure for sweet itch. If you believe your horse or pony suffers from sweet itch, we recommend calling your vet to talk through management and treatment options.

This article also appears on the Horse Health Programme website.